Currently, there are many kinds of sensors for detecting light, among which light-sensitive sensors are more prominent ones. However, there are fewer kinds of light sensors that may be integrated on glass substrates. Light sensitive characteristics of thin film transistors made of different materials are different. For example, amorphous silicon (A-Si) has the best light sensitive characteristic, and a low-temperature polysilicon and back channel etch (BCE) thin film transistor has a better inert characteristic to light.